We retrospectively analyzed the echocardiographic findings of 8 patients with atrial thrombus (AT). This study was conducted in Yijishan Hospital between January 2019 and September 2021. Of the 8 patients, right atrial mass was detected in 4 patients, and left atrial mass was detected in the rest 4 patients. All masses were initially diagnosed as myxoma, which were later confirmed as thrombus. Athough echocardiography can provide significant information about the nature of atrial mass in many patients, a small percentage of atrial masses remain difficult to make a qualitative diagnosis.